Diphyllin is a natural arylnaphtalide lignan extracted from tropical plants of particular importance in traditional Chinese medicine. This compound has been described as a potent inhibitor of vacuolar (H⁺)ATPases and hence of the endosomal acidification process that is required by numerous enveloped viruses to trigger their respective viral infection cascades after entering host cells by receptor-mediated endocytosis. Accordingly, we report here a revised, updated, and improved synthesis of diphyllin, and demonstrate its antiviral activities against a panel of enveloped viruses from Flaviviridae, Phenuiviridae, Rhabdoviridae, and Herpesviridae families. Diphyllin is not cytotoxic for Vero and BHK-21 cells up to 100 µM and exerts a sub-micromolar or low-micromolar antiviral activity against tick-borne encephalitis virus, West Nile virus, Zika virus, Rift Valley fever virus, rabies virus, and herpes-simplex virus type 1. Our study shows that diphyllin is a broad-spectrum host cell-targeting antiviral agent that blocks the replication of multiple phylogenetically unrelated enveloped RNA and DNA viruses. In support of this, we also demonstrate that diphyllin is more than just a vacuolar (H⁺)ATPase inhibitor but may employ other antiviral mechanisms of action to inhibit the replication cycles of those viruses that do not enter host cells by endocytosis followed by low pH-dependent membrane fusion.

This present mini-review covers recently published results on Cu(I) and Cu(II) complexes immobilized on polystyrene carriers, which are used as heterogeneous, eco-friendly reusable catalysts applied for carbon–carbon and carbon–nitrogen forming reactions. Recent advances and trends in this area are demonstrated in the examples of oxidative homocoupling of terminal alkynes, the synthesis of propargylamines, nitroaldolization reactions, azide alkyne cycloaddition, N-arylation of nitrogen containing compounds, aza-Michael additions, asymmetric Friedel–Crafts reactions, asymmetric Mukaiyama aldol reactions, and asymmetric 1,3-dipolar cycloaddition of azomethine ylides. The type of polystyrene matrix used for the immobilization of complexes is discussed in this paper, and particularly, the efficiency of the catalysts from the point of view of the overall reaction yield, and possible enantioselectivity and potential reusing, is reviewed.

Poly(ethylene glycol)s are well defined and easily accessible macromolecules with suitable properties for applications in chemistry, biotechnologies and medicine. The terminal hydroxy groups of poly(ethylene glycol)s can easily be converted into reactive functional groups by a number of routine reactions of organic chemistry. The chemical reagents or catalysts anchored to poly(ethylene glycol) chains were used in a number of syntheses including the enantioselective ones. Poly(ethylene glycol)s serve as carriers in combinatorial syntheses in the liquid phase. Coupling of poly(ethylene glycol)s with other polymers was used to prepare series of block copolymers having numerous applications. From the point of view of medical applications it is significant that substituted poly(ethylene glycol)s are non-toxic and resistant to recognition by the immunity system. That is why they are often used as carriers of many low-molecular-weight as well as high-molecular-weight medical drugs (drug delivery systems). In the conjugates with drugs their biological activity increases and their toxicity decreases. A review with 41 references.